大约有 40,000 项符合查询结果（耗时：0.0518秒） [XML]
Why does one hot encoding improve machine learning performance?
...h" and "US". Assume, without loss of generality, that these are encoded as 0, 1 and 2. You then have a weight w for this feature in a linear classifier, which will make some kind of decision based on the constraint w×x + b > 0, or equivalently w×x < b.
The problem now is that the weight w c...
Check if UIColor is dark or bright?
...o use is ((Red value * 299) + (Green value * 587) + (Blue value * 114)) / 1000.
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Creating a comma separated list from IList or IEnumerable
...ng"};
string joined = string.Join(",", strings);
Detail & Pre .Net 4.0 Solutions
IEnumerable<string> can be converted into a string array very easily with LINQ (.NET 3.5):
IEnumerable<string> strings = ...;
string[] array = strings.ToArray();
It's easy enough to write the equiv...
dplyr summarise: Equivalent of “.drop=FALSE” to keep groups with zero length in output
...
Since dplyr 0.8 group_by gained the .drop argument that does just what you asked for:
df = data.frame(a=rep(1:3,4), b=rep(1:2,6))
df$b = factor(df$b, levels=1:3)
df %>%
group_by(b, .drop=FALSE) %>%
summarise(count_a=length(a)...
Validate decimal numbers in JavaScript - IsNumeric()
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2908
@Joel's answer is pretty close, but it will fail in the following cases:
// Whitespace strings...
Format number to 2 decimal places
...
You want to use the TRUNCATE command.
https://dev.mysql.com/doc/refman/8.0/en/mathematical-functions.html#function_truncate
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Common MySQL fields and their appropriate data types
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answered Dec 10 '08 at 0:57
da5idda5id
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How to read the content of a file to a string in C?
...-codes for fseek, ftell and fread. (omitted for clarity).
char * buffer = 0;
long length;
FILE * f = fopen (filename, "rb");
if (f)
{
fseek (f, 0, SEEK_END);
length = ftell (f);
fseek (f, 0, SEEK_SET);
buffer = malloc (length);
if (buffer)
{
fread (buffer, 1, length, f);
}
fclo...
Generate a Hash from string in Javascript
...perty(String.prototype, 'hashCode', {
value: function() {
var hash = 0, i, chr;
for (i = 0; i < this.length; i++) {
chr = this.charCodeAt(i);
hash = ((hash << 5) - hash) + chr;
hash |= 0; // Convert to 32bit integer
}
return hash;
}
});
Source:
htt...
Imply bit with constant 1 or 0 in SQL Server
Is it possible to express 1 or 0 as a bit when used as a field value in a select statement?
8 Answers
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